#include "codeforces.h"
#include <chrono>
#include <vector>

using namespace std;
using namespace std::chrono_literals;
using namespace cf;

int main() {
    Blog announcement("Codeforces Round 1119 (Div. 3)");

    announcement << "Hello Codeforces!\n";
    announcement << "I am delighted to invite you to participate in " << Codeforces Round (Div. 3) << "!\n";
    announcement << "The problems were written and prepared by " << nik_exists << ".\n\n";

    announcement << ContestInfo {
        .start_time = Sep/05/2026 17:35 (Moscow time),
        .duration = 2h + 15min,
        .number_of_problems = 7,
        .subtasks = true // possibly not adjacent
    };

    announcement << RatingRules {
        .rated_for_rating_below = 1600,
        .unrated_registration_allowed = true,
        .trusted_max_rating_below = 1900,
        .trusted_min_rated_rounds = 5
    };

    announcement << JudgingRules {
        .scoring = codeforces::ICPC,
        .wrong_answer_penalty = 10min,
        .open_hacking_phase = 12h,
        .final_tests = after_open_hacks
    };

    auto is_cheater = [](User user) {
        // https://codeforces.me/blog/entry/133941
        if (user.used_ai_in_contest()) return true;
        if (user.discussed_problems_online_before_contest_end()) return true;
        if (user.violated_other_rules_im_too_lazy_to_list()) return true;
        return false;
    };

    for (auto user : get_users(2259)) {
        if (is_cheater(user)) user.send_to_cry_basement();
    }

    announcement << Acknowledgements {
        .coordinator = cry,
        .russian_translation = Vladosiya,
        .red_testers = {__baozii__, AksLolCoding, awesomeguy856, nifeshe},
        .golden_testers = {Arpa, Proof_by_QED, temporary1},
        .purple_testers = {Argentum47, Euclid73, Jteh, Lilypad, SpyrosAliv, nimoxide, omsincoconut, wakanda-forever, yse},
        .blue_testers = {CatsAreCool, Vladosiya, chromate00, fatespeaker, linearspace, reirugan, simplelife},
        .green_testers = {hannah12345},
        .codeforces_and_polygon = {KAN, MikeMirzayanov}
    };

    announcement << "\nBest of luck, and thank y'all so much for competing!\n";
}

Приветствуем вас, фанаты олимпиадного программирования и любители написать раунды на Codeforces! У нас еще нет для вас раунда (это грустно), но зато есть кружок (это круто), где вы сможете обучиться новым алгоритмам, прорешать интересные задачи и многое другое!

Но даже без раунда перед постом хочется выразить благодарность MikeMirzayanov и команде Codeforces за замечательные системы Polygon и Codeforces! Благодаря этим системам, у нас есть возможность проводить кружок.

Т-Поколение "Алгоритмы и структуры данных" — это бесплатный кружок по подготовке к олимпиадам по информатике и спортивному программированию. Кружок проходит как онлайн, так и очно в Москве, Санкт-Петербурге, Нижнем Новгороде, Казани, Саратове, Ижевске, Перми, Уфе, Екатеринбурге, Челябинске, Томске, Новосибирске и даже в Минске. Учебная программа делится на 5 параллелей по уровню обучающихся:

• Параллель X предназначена для опытных олимпиадников, в ней преподают: Бабин teraqqq Александр, Нагибин Pechalka Всеволод, Белый antonis.white Антон.

• Параллель XS предназначена для тех, кто боится идти учиться в параллель X, но все равно хочет подготовиться к выступлению на финале ВсОШ. В этой параллели преподают: Грекова arbuzick Дарья, Белоусько Alcabel Константин, Валиуллин sadness Данис и Чистяков alexchist Александр.

• Параллель B предназначена для тех, кто уверенно проходит на региональный этап ВсОШ, хочет научиться проходить на заключительный этап и брать там диплом призера. В этой параллели преподают: Паншин doing Игорь, Сарапкин ArSarapkin Артем, Евстигнеев LargestNaturalNumber Георгий и Бессолицын BottleOfJuice Максим.

• Параллель B' предназначена для тех, кто на базовом уровне владеет C++, участвовал в муниципальных этапах ВсОШ и хочет подготовиться к региональному этапу ВсОШ и перечневым олимпиадам. В этой параллели преподают: Подворный Иван, Волков Smurf_with_me Алексей, Шейкис dope Марк и Хазеев ilgizarka Ильгизар.

• Параллель C предназначена для тех, кто на базовом уровне владеет Python или C++ и только начал свой путь в олимпиадном программировании. В этой параллели преподают: Ремпель DimaTomsk Дмитрий, Кривощеков robivirt Виктор, Антонова anadere Анна, Вашуркин Emvy Макар, Шатохин FedShat Фёдор и Чудинова Maria_Chudinova Мария.

Если вы готовы вкладывать свое время и старание в обучение, хотите взять всерос любой ценой, но бесплатно, то вам точно у нас понравится. Мы раздаем много мерча, преподаватели — опытные участники олимпиад высочайшего уровня, как в школьные, так и в студенческие годы, поэтому вам точно будет, чему у них научиться.

С правилами отбора вы можете ознакомиться по ссылке, 5 сентября, 16:00–21:00 по МСК будет очный отбор на все параллели. На него надо зарегистрироваться заранее и он будет проходить в очном+дистанционном формате тура на 5 часов.

Ссылка на отбор

Merhaba Codeforces!

We are proud to invite you to Codeforces Round 1118 (Div. 2), which will be held on Aug/29/2026 17:35 (Moscow time).

The round will be rated for participants whose rating is below 2100, but higher rated users are also welcome to participate out of competition. You will be given 6 problems, one of which will be divided into a subtask, and 2 hours to solve them. Also, there is at least one interactive problem, so you are recommended to read the guide to interactive problems if you have not encountered them before.

The problems were authored by me (ItsNotMeItsYou), carcinisation, mychecksdead and Seferoglu.

This round was prepared by some members of the 2025 and 2026 IOI team of Türkiye, and we hope you enjoy all our problems.

We would like to thank:

• cadmiumky for his outstanding coordination of the round,

• Um_nik for the preliminary review,

• Alexdat2000 for Russian translations,

• MikeMirzayanov and KAN for Codeforces and Polygon,

• Our testers: destructive_criticism, tolbi, dinohaur, anpaio, kalimm, nifeshe, https, kafamcokkaristi, FatihCihan, LucaLucaM, PieArmy, int23_t, temporary1, robert9524, Kel_Mahmut, dead0ne, kawasaki, Synd209, elotelo, Anfeco,

• anpaio for improving at least one problem,

• destructive_criticism and dinohaur for at least one unused suggestion,

• You for participating in the round.

Score distribution: $$$500-(750+1000)-1250-2000-2250-3000$$$

Good luck & have fun!

UPD: The editorial is out! Sorry for underestimating the difficulties of the problems, especially B2 and D. We tried to serve as many cool problems as we could. And apparently, this led to some difficult ones.

Congratulations to the winners:

Official participants (subjects to change):

• xl123
• BTinn
• asterunee
• Alexander_0918
• no-girlfriend

Unofficial participants (subjects to change):

• xl123
• PiGoat
• BTinn
• maspy
• asterunee

Hello, Codeforces!

We are happy to invite you to an exciting online event: ICPC Online Challenge powered by Huawei.

This Challenge features the problem

Scheduling Algorithm for Collaborative Inference System With the rapid advancement of artificial intelligence, large language model (LLM) services are becoming increasingly integrated into people’s daily lives and work. At the same time, the economic efficiency and data security of these services are receiving greater attention.

Edge-Cloud Collaborative Inference has emerged as a promising approach to addressing these challenges. In this architecture, LLM inference is divided between a user’s on-premises edge environment and the cloud. Using a U-shaped split, the first and last layers of the model run on the edge, while the computationally intensive middle layers run in the cloud. This allows private inputs and outputs to remain on the user’s side while cloud resources are used for the heavier computation.

However, this architecture requires repeated interaction between the edge and the cloud during both the prefill and decoding stages. When requests are processed sequentially, these interactions can create “bubbles”—periods in which computing resources remain idle while waiting for other parts of the system.

Your challenge is to design a concurrent scheduling strategy that:

• maximizes overall system throughput; and
• ensures that every request satisfies its latency Service Level Objective (SLO).

Participants will need to carefully coordinate computation and communication across the edge and cloud while balancing throughput and per-request latency requirements.

We hope you will enjoy this challenging optimization problem inspired by real-world AI infrastructure.

Start: August 14, 2026 11:00 UTC (UTC+0)

Finish: August 28, 2026 10:59 UTC (UTC+0)

Prizes

By participating in this Challenge, you agree to the official Rules.

The use of AI tools, including generative AI and AI-assisted coding tools, is permitted during the Challenge. Participants remain fully responsible for the correctness, originality, and compliance of their submissions with all applicable rules.

To be eligible for a prize, you must register through: https://icpc.global/regionals/finder/ICPC-Online-Challenge-2026.

If you cannot access the rules document, please contact [email protected].

Good luck, and we hope you enjoy this complex yet exciting Challenge!

💻 Are you ready to test your problem-solving skills and push your limits in the world of algorithms and data processing? The Technology Olympics 2026 brings you two exciting competitions where creativity, logic, and technical mastery meet high-level challenges—and top teams win prizes!

🎈 Algorithm Track

• Preliminary Round (Online): Friday, September 25, 2026
• Final Round (Onsite – Tehran, Iran): Wednesday, November 3, 2026
• Closing Ceremony: Thursday, November 4, 2026

The problems were authored and prepared by alireza_kaviani, eren__, ArshiaDadras, AlefHeKaaf and AiPd.

📊 Data Processing Track

• Preliminary Round (Online – 24 Hours): Friday, September 11, 2026
• Final Round (Onsite – Tehran, Iran): Thursday, November 4, 2026
• Closing Ceremony: Thursday, November 4, 2026

🏆 Prizes for Each Track

Top 5 Teams in Preliminary Round:

• Travel support to Tehran (up to $200 per person)
• Hotel accommodation during the onsite final
• Meals and refreshments during the event
• Teams ranked 6th to 10th will also qualify for the onsite final

Cash prizes:

• 🥇 1st: $600
• 🥈 2nd: $450
• 🥉 3rd: $300
• 🏅 4th: $250
• 🏅 5th: $200

Cash prizes will be awarded upon participation in the onsite final. Qualified international teams will also receive travel and accommodation support according to the rules of each track, including:

• Travel support to Tehran (up to $200 per person)

• Hotel accommodation during the onsite final

• Meals and refreshments during the event

• Teams ranked 6th to 10th will also qualify for the onsite final.

• Qualified teams will be invited to an online briefing webinar before the final round, covering competition rules, travel arrangements, event schedules, submission procedures, evaluation criteria, and other logistical details.

Привет, Codeforces!

Мы рады объявить, что в 17.08.2026 17:35 (Московское время) начнётся Codeforces Round 1117 (Div. 2) — очередной раунд для второго дивизиона. Этот раунд будет рейтинговым для всех участников с рейтингом ниже $$$2100$$$. Вам будет дано $$$2$$$ часа на решение $$$6$$$ задач, некоторые из которых будут разделены на подзадачи.

Все задачи были придуманы и подготовлены egorka5opka, oblememan и мной.

Также большое спасибо:

• Akulyat за координацию раунда;
• Um_nik за предварительное ревью раунда;
• Нашим тестерам: 300iq, __baozii__, Tizz1e, Friendiks, _icy_, Wileyne, Megnis, omsincoconut, _istil, AksLolCoding, madlogic за их время и усилия, потраченные на тестирование задач.

Распределение баллов приведено ниже.

$$$500-750-1250-1750−2250−(2750+1000)$$$

GLHF!

UPD Для тех, кого затронули некорректные ограничения в задаче D и кто хочет, чтобы раунд не влиял на их рейтинг, пожалуйста, оставьте комментарий "Я хочу, чтобы этот раунд не влиял на мой рейтинг" в разделе "Задать вопрос" на главной странице контеста под задачами. Это относится только к тем, кого ошибка действительно затронула, то есть вы должны были получить TL (или другой соответсвующий вердикт) по этой задаче.

UPD2 Разбор

UPD3 Победители и First to solve

Официальные участники:

Неофициальные участники:

First to solve:

Hello, Codeforces!

We are glad to invite you to participate in Codeforces Round 1116 (Div. 1) and Codeforces Round 1116 (Div. 2) on Aug/09/2026 17:35 (Moscow time).

The round will be rated for participants from both divisions. You will be given 6 problems and 2 hours and 30 minutes to solve them. At least one of the problems will be divided into subtasks.

Please note that this contest contains at least one run-twice (communication) problem. Please read the guides for run-twice problems before the contest if you are unfamiliar with them.

All problems were authored and prepared by Error_Yuan and me, paulzrm.

More than eight years after Codeforces Round 449, Chtholly Nota Seniorious — the happiest girl in the world — is returning to Codeforces!

In this round, you will once again meet Chtholly, Nephren, Ithea, Willem, and other characters from What Do You Do at the End of the World? Are You Busy? Will You Save Us?, and help them overcome a new series of challenges.

We would like to thank:

• Error_Yuan for his excellent coordination, patient guidance, and invaluable help throughout the preparation of the round.

• Alexdat2000 for translating the statements to Russian.

• HugeWide, my teammate, for VIP testing and for all his help throughout the preparation of the round.

• HHH666666, XG0000, Mitsukasa_Ayase, zt17, a_little_cute, aaa_Pigeon2, StarSilk, tiger2005, Proof_by_QED, _istil, nifeshe, floptron1, arvindr9 and WorldWarV for testing the round and providing valuable feedback.

• KAN and MikeMirzayanov for the great Codeforces and Polygon platforms.

• You

  for participating in this round.

The scoring distribution will be announced later.

We hope you enjoy the problems and Chtholly’s story.

Good luck and have fun!

UPD1: The Scoring distribution is:

• Div. 1: 500 — 1000 — 1750 — 1750 — (1750 + 1250) — 3500
• Div. 2: 500 — 1000 — 1500 — 2000 — 2750 — 3000

UPD2: The editorial is out.

UPD3: Congratulations to the winners!

Div. 1 (subject to change):

1. turmax
2. noimi
3. maspy
4. squareOf105
5. Milmon

Div. 2 (subject to change):

1. lvsedeqinglvse
2. Cucumber0721
3. Smarth_coder
4. asterunee
5. Chth_kitten

We would also like to congratulate the first solvers of each problem (subject to change):

1. Div. 2 A: Forestmy17 00:01
2. Div. 2 B: asterunee 00:04
3. Div. 1 A / Div. 2 C: A_G 00:02
4. Div. 1 B / Div. 2 D: maspy 00:05
5. Div. 1 C / Div. 2 E: literalchild 00:19
6. Div. 1 D / Div. 2 F: de1uxegg 00:23
7. Div. 1 E1: __baozii__ 01:02
8. Div. 1 E2: ABCaCaCa_ 01:10
9. Div. 1 F: turmax 01:34

Привет, Codeforces!

Благодаря поддержке Neapolis University Pafos, продолжается серия образовательных раундов. Университет предлагает получение степени бакалавра в области компьютерных наук и искусственного интеллекта со стипендиями JetBrains. Получите передовые навыки в области искусственного интеллекта и машинного обучения, которые подготовят вас к востребованным техническим карьерам. Доступно ограниченное количество стипендий. Не упустите свой шанс учиться в Европе бесплатно!

В 07.08.2026 17:35 (Московское время) состоится Educational Codeforces Round 193 (Rated for Div. 2).

Этот раунд будет рейтинговым для участников с рейтингом менее 2100. Соревнование будет проводиться по немного расширенным правилам ICPC. Штраф за каждую неверную посылку до посылки, являющейся полным решением, равен 10 минутам. После окончания раунда будет период времени длительностью в 12 часов, в течение которого вы можете попробовать взломать абсолютно любое решение (в том числе свое). Причем исходный код будет предоставлен не только для чтения, но и для копирования.

Вам будет предложено 6 задач на 2 часа. Мы надеемся, что вам они покажутся интересными.

Задачи вместе со мной придумывал и готовил Максим FelixArg Новоточинов.

Выражаем огромную благодарность Михаилу MikeMirzayanov Мирзаянову — создателю платформ Codeforces и Polygon, без которых этого раунда (и в целом серии образовательных раундов) бы не было.

Также большое спасибо тестерам раунда: awoo, Alenochka, pusheen_1024, savolay, yegor.l!

Удачи в раунде! Успешных решений!

upd: Разбор можно найти здесь.

Hello, Codeforces!

We are excited to invite you to participate in Codeforces Round 1115 (Div. 2), which will take place on Aug/06/2026 17:35 (Moscow time).

The round will be rated for all participants with a rating below 2100. Participants from Division 1 are warmly welcome to participate unofficially.

You will be given 6 problems and 2 hours to solve them.

The round was prepared by TomitaMatei and me, Bufu.

We would like to express our deepest gratitude to everyone who made this round possible:

• cry for their excellent coordination and infinite patience while reviewing the problems!

• Alexdat2000 for translating the statements to Russian.

• Um_nik and KAN for pre-reviewing the round!

• Our wonderful team of testers for solving the problems and providing highly valuable feedback: Intellegent, awesomeguy856, _istil, andrei_n, Friedrich, __baozii__, simplelife, omsincoconut, madlogic, nik_exists, Edeeva, SpyrosAliv, and Argentum47.

• MikeMirzayanov and KAN for creating and maintaining the amazing Codeforces and Polygon platforms!

• You for participating in the round!

The score distribution will be:

$$$500$$$ — $$$1000$$$ — $$$1250$$$ — $$$1750$$$ — $$$2250$$$ — $$$2750$$$

Good luck, have fun, and may the rating be with you!

UPD: Congratulations to the winners!

Unofficial participants:

1. abc864197532

2. Rubikun

3. maspy

4. CryptoQuant

5. Lynkcat

Official participants: (subject to change)

1. Kodik

2. sahajoydeep467

3. Wonter

4. jeduardobras

5. Gemini17

UPD 2: The editorial is now available!

Hello, Codeforces!

I am very excited to invite you to participate in Codeforces Round 1114 (Div. 3), which will take place on Aug/04/2026 17:35 (Moscow time). You will be given $$$2$$$ hours and $$$15$$$ minutes to solve $$$7$$$ problems, where one problem will be split into subtasks. All problems were authored and prepared by me.

The round will be hosted by rules of educational rounds (extended ICPC). Thus, all solutions will be judged on preliminary tests during the round, and after the round, there will be a 12-hour phase of open hacks. After the open hack phase, all accepted solutions will be rejudged on successful hacks. Also, note that there is no score distribution but the usual penalty of 10 minutes for each wrong submission, following the rules of educational rounds.

Remember that only the trusted participants of the third division will be included in the official standings table. As it is written by link, this is a compulsory measure for combating unsporting behavior. To qualify as a trusted participant of the third division, you must:

• take part in at least five rated rounds (and solve at least one problem in each of them)
• do not have a rating of 1900 or higher at any moment in time.

Regardless of whether you are a trusted participant of the third division or not, if your rating is less than 1600, then the round will be rated for you (unless you register unrated).

I would like to thank the following people for making this round possible:

• cry for coordinating the round;
• __baozii__ for red testing;
• temporary1, Proof_by_QED for orange testing;
• SpyrosAliv, Argentum47, Friedrich, omsincoconut, wakanda-forever, reirugan, cgmoreda for purple testing;
• DivinePunishment, Mousa, Wageeh, wuhudsm, chromate00, detective...dots, Borhom for blue testing;
• Mr_Bald, ALnQ417 for cyan testing;
• Vladosiya for statement translation and testing;
• MikeMirzayanov for developing Codeforces and Polygon.

Good luck, and most importantly, have fun!

Update: Tutorial